Work around deadlock when destroying J2KEncoder with a full writer queue (#2784).
[dcpomatic.git] / src / lib / encode_server_finder.cc
index 06a6a396b1ae75161d6cbe940b585ae18b335083..1d4ced5951f01315306259a861bf2c5645b94aa5 100644 (file)
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2013-2018 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2021 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
 
 */
 
-#include "encode_server_finder.h"
-#include "exceptions.h"
-#include "util.h"
+
 #include "config.h"
+#include "constants.h"
 #include "cross.h"
-#include "encode_server_description.h"
 #include "dcpomatic_socket.h"
+#include "encode_server_description.h"
+#include "encode_server_finder.h"
+#include "exceptions.h"
 #include <dcp/raw_convert.h>
 #include <libcxml/cxml.h>
+#include <boost/bind/placeholders.hpp>
 #include <boost/lambda/lambda.hpp>
 #include <iostream>
 
 #include "i18n.h"
 
-using std::string;
+
+using std::cout;
 using std::list;
+using std::make_shared;
+using std::shared_ptr;
+using std::string;
 using std::vector;
-using std::cout;
-using boost::shared_ptr;
-using boost::scoped_array;
-using boost::weak_ptr;
+using std::weak_ptr;
 using boost::optional;
+using boost::scoped_array;
+#if BOOST_VERSION >= 106100
+using namespace boost::placeholders;
+#endif
 using dcp::raw_convert;
 
+
 EncodeServerFinder* EncodeServerFinder::_instance = 0;
 
+
 EncodeServerFinder::EncodeServerFinder ()
-       : _search_thread (0)
-       , _listen_thread (0)
-       , _stop (false)
+       : _stop (false)
 {
        Config::instance()->Changed.connect (boost::bind (&EncodeServerFinder::config_changed, this, _1));
 }
 
+
 void
 EncodeServerFinder::start ()
 {
-       _search_thread = new boost::thread (boost::bind (&EncodeServerFinder::search_thread, this));
-       _listen_thread = new boost::thread (boost::bind (&EncodeServerFinder::listen_thread, this));
+       _search_thread = boost::thread (boost::bind(&EncodeServerFinder::search_thread, this));
+       _listen_thread = boost::thread (boost::bind(&EncodeServerFinder::listen_thread, this));
 #ifdef DCPOMATIC_LINUX
-       pthread_setname_np (_search_thread->native_handle(), "encode-server-search");
-       pthread_setname_np (_listen_thread->native_handle(), "encode-server-listen");
+       pthread_setname_np (_search_thread.native_handle(), "encode-server-search");
+       pthread_setname_np (_listen_thread.native_handle(), "encode-server-listen");
 #endif
 }
 
@@ -69,63 +77,35 @@ EncodeServerFinder::~EncodeServerFinder ()
        stop ();
 }
 
+
 void
 EncodeServerFinder::stop ()
 {
+       boost::this_thread::disable_interruption dis;
+
        _stop = true;
 
        _search_condition.notify_all ();
-       if (_search_thread) {
-               /* Ideally this would be a DCPOMATIC_ASSERT(_search_thread->joinable()) but we
-                  can't throw exceptions from a destructor.
-               */
-               if (_search_thread->joinable ()) {
-                       _search_thread->join ();
-               }
-       }
-       delete _search_thread;
-       _search_thread = 0;
+       try {
+               _search_thread.join();
+       } catch (...) {}
 
        _listen_io_service.stop ();
-       if (_listen_thread) {
-               /* Ideally this would be a DCPOMATIC_ASSERT(_listen_thread->joinable()) but we
-                  can't throw exceptions from a destructor.
-               */
-               if (_listen_thread->joinable ()) {
-                       _listen_thread->join ();
-               }
-       }
-       delete _listen_thread;
-       _listen_thread = 0;
+       try {
+               _listen_thread.join ();
+       } catch (...) {}
 
        boost::mutex::scoped_lock lm (_servers_mutex);
-       _good_servers.clear ();
-       _bad_servers.clear ();
+       _servers.clear ();
 }
 
-static bool
-remove_missing (list<EncodeServerDescription>& servers, int since)
-{
-       bool removed = false;
-       list<EncodeServerDescription>::iterator i = servers.begin();
-       while (i != servers.end()) {
-               if (i->last_seen_seconds() > since) {
-                       list<EncodeServerDescription>::iterator j = i;
-                       ++j;
-                       servers.erase (i);
-                       i = j;
-                       removed = true;
-               } else {
-                       ++i;
-               }
-       }
-       return removed;
-}
 
 void
 EncodeServerFinder::search_thread ()
 try
 {
+       start_of_thread ("EncodeServerFinder-search");
+
        boost::system::error_code error;
        boost::asio::io_service io_service;
        boost::asio::ip::udp::socket socket (io_service);
@@ -134,52 +114,60 @@ try
                throw NetworkError ("failed to set up broadcast socket");
        }
 
-        socket.set_option (boost::asio::ip::udp::socket::reuse_address (true));
-        socket.set_option (boost::asio::socket_base::broadcast (true));
+        socket.set_option (boost::asio::ip::udp::socket::reuse_address(true));
+        socket.set_option (boost::asio::socket_base::broadcast(true));
 
        string const data = DCPOMATIC_HELLO;
        int const interval = 10;
 
        while (!_stop) {
-               if (Config::instance()->use_any_servers ()) {
+               if (Config::instance()->use_any_servers()) {
                        /* Broadcast to look for servers */
                        try {
                                boost::asio::ip::udp::endpoint end_point (boost::asio::ip::address_v4::broadcast(), HELLO_PORT);
-                               socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
+                               socket.send_to (boost::asio::buffer(data.c_str(), data.size() + 1), end_point);
                        } catch (...) {
 
                        }
                }
 
                /* Query our `definite' servers (if there are any) */
-               vector<string> servers = Config::instance()->servers ();
-               for (vector<string>::const_iterator i = servers.begin(); i != servers.end(); ++i) {
-                       if (server_found (*i)) {
-                               /* Don't bother asking a server that we already know about */
-                               continue;
-                       }
+               for (auto const& i: Config::instance()->servers()) {
                        try {
                                boost::asio::ip::udp::resolver resolver (io_service);
-                               boost::asio::ip::udp::resolver::query query (*i, raw_convert<string> (HELLO_PORT));
-                               boost::asio::ip::udp::endpoint end_point (*resolver.resolve (query));
-                               socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
+                               boost::asio::ip::udp::resolver::query query (i, raw_convert<string>(HELLO_PORT));
+                               boost::asio::ip::udp::endpoint end_point (*resolver.resolve(query));
+                               socket.send_to (boost::asio::buffer(data.c_str(), data.size() + 1), end_point);
                        } catch (...) {
 
                        }
                }
 
                /* Discard servers that we haven't seen for a while */
+               bool removed = false;
                {
                        boost::mutex::scoped_lock lm (_servers_mutex);
-                       bool g = remove_missing(_good_servers, 2 * interval);
-                       bool b = remove_missing(_bad_servers, 2 * interval);
-                       if (g || b) {
-                               emit (boost::bind (boost::ref (ServersListChanged)));
+
+                       auto i = _servers.begin();
+                       while (i != _servers.end()) {
+                               if (i->last_seen_seconds() > 2 * interval) {
+                                       auto j = i;
+                                       ++j;
+                                       _servers.erase (i);
+                                       i = j;
+                                       removed = true;
+                               } else {
+                                       ++i;
+                               }
                        }
                }
 
+               if (removed) {
+                       emit (boost::bind(boost::ref(ServersListChanged)));
+               }
+
                boost::mutex::scoped_lock lm (_search_condition_mutex);
-               _search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds (interval));
+               _search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds(interval));
        }
 }
 catch (...)
@@ -187,14 +175,17 @@ catch (...)
        store_current ();
 }
 
+
 void
 EncodeServerFinder::listen_thread ()
 try {
+       start_of_thread ("EncodeServerFinder-listen");
+
        using namespace boost::asio::ip;
 
        try {
                _listen_acceptor.reset (
-                       new tcp::acceptor (_listen_io_service, tcp::endpoint (tcp::v4(), is_batch_converter ? BATCH_SERVER_PRESENCE_PORT : MAIN_SERVER_PRESENCE_PORT))
+                       new tcp::acceptor (_listen_io_service, tcp::endpoint(tcp::v4(), is_batch_converter ? BATCH_SERVER_PRESENCE_PORT : MAIN_SERVER_PRESENCE_PORT))
                        );
        } catch (...) {
                boost::throw_exception (NetworkError (_("Could not listen for remote encode servers.  Perhaps another instance of DCP-o-matic is running.")));
@@ -208,79 +199,77 @@ catch (...)
        store_current ();
 }
 
+
 void
 EncodeServerFinder::start_accept ()
 {
-       shared_ptr<Socket> socket (new Socket ());
+       _accept_socket = make_shared<Socket>();
+
        _listen_acceptor->async_accept (
-               socket->socket(),
-               boost::bind (&EncodeServerFinder::handle_accept, this, boost::asio::placeholders::error, socket)
+               _accept_socket->socket(),
+               boost::bind(&EncodeServerFinder::handle_accept, this, boost::asio::placeholders::error)
                );
 }
 
+
 void
-EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Socket> socket)
+EncodeServerFinder::handle_accept (boost::system::error_code ec)
 {
        if (ec) {
                start_accept ();
                return;
        }
 
-       uint32_t length;
-       socket->read (reinterpret_cast<uint8_t*> (&length), sizeof (uint32_t));
-       length = ntohl (length);
-
-       scoped_array<char> buffer (new char[length]);
-       socket->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
+       string server_available;
 
-       string s (buffer.get());
-       shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
-       xml->read_string (s);
+       try {
+               uint32_t length;
+               _accept_socket->read (reinterpret_cast<uint8_t*>(&length), sizeof(uint32_t));
+               length = ntohl (length);
 
-       string const ip = socket->socket().remote_endpoint().address().to_string ();
-       optional<list<EncodeServerDescription>::iterator> found = server_found (ip);
-       if (found) {
-               (*found)->set_seen ();
-       } else {
-               EncodeServerDescription sd (ip, xml->number_child<int>("Threads"), xml->optional_number_child<int>("Version").get_value_or(0));
-               if (sd.link_version() == SERVER_LINK_VERSION) {
-                       boost::mutex::scoped_lock lm (_servers_mutex);
-                       _good_servers.push_back (sd);
-               } else {
-                       boost::mutex::scoped_lock lm (_servers_mutex);
-                       _bad_servers.push_back (sd);
+               if (length > 65536) {
+                       start_accept();
+                       return;
                }
-               emit (boost::bind (boost::ref (ServersListChanged)));
-       }
-
-       start_accept ();
-}
 
-optional<list<EncodeServerDescription>::iterator>
-EncodeServerFinder::server_found (string ip)
-{
-       boost::mutex::scoped_lock lm (_servers_mutex);
-       list<EncodeServerDescription>::iterator i = _good_servers.begin();
-       while (i != _good_servers.end() && i->host_name() != ip) {
-               ++i;
+               scoped_array<char> buffer(new char[length]);
+               _accept_socket->read (reinterpret_cast<uint8_t*>(buffer.get()), length);
+               server_available = buffer.get();
+       } catch (NetworkError&) {
+               /* Maybe the server went away; let's just try again */
+               start_accept();
+               return;
        }
 
-       if (i != _good_servers.end()) {
-               return i;
-       }
+       auto xml = make_shared<cxml::Document>("ServerAvailable");
+       xml->read_string(server_available);
 
-       i = _bad_servers.begin();
-       while (i != _bad_servers.end() && i->host_name() != ip) {
-               ++i;
+       auto const ip = _accept_socket->socket().remote_endpoint().address().to_string();
+       bool changed = false;
+       {
+               boost::mutex::scoped_lock lm (_servers_mutex);
+               auto i = _servers.begin();
+               while (i != _servers.end() && i->host_name() != ip) {
+                       ++i;
+               }
+
+               if (i != _servers.end()) {
+                       i->set_seen();
+               } else {
+                       EncodeServerDescription sd (ip, xml->number_child<int>("Threads"), xml->optional_number_child<int>("Version").get_value_or(0));
+                       _servers.push_back (sd);
+                       changed = true;
+               }
        }
 
-       if (i != _bad_servers.end()) {
-               return i;
+       if (changed) {
+               emit (boost::bind(boost::ref (ServersListChanged)));
        }
 
-       return optional<list<EncodeServerDescription>::iterator>();
+       start_accept ();
 }
 
+
 EncodeServerFinder*
 EncodeServerFinder::instance ()
 {
@@ -292,35 +281,30 @@ EncodeServerFinder::instance ()
        return _instance;
 }
 
+
 void
 EncodeServerFinder::drop ()
 {
        delete _instance;
-       _instance = 0;
+       _instance = nullptr;
 }
 
-list<EncodeServerDescription>
-EncodeServerFinder::good_servers () const
-{
-       boost::mutex::scoped_lock lm (_servers_mutex);
-       return _good_servers;
-}
 
 list<EncodeServerDescription>
-EncodeServerFinder::bad_servers () const
+EncodeServerFinder::servers () const
 {
        boost::mutex::scoped_lock lm (_servers_mutex);
-       return _bad_servers;
+       return _servers;
 }
 
+
 void
 EncodeServerFinder::config_changed (Config::Property what)
 {
        if (what == Config::USE_ANY_SERVERS || what == Config::SERVERS) {
                {
                        boost::mutex::scoped_lock lm (_servers_mutex);
-                       _good_servers.clear ();
-                       _bad_servers.clear ();
+                       _servers.clear ();
                }
                ServersListChanged ();
                _search_condition.notify_all ();